have you run a windows 7 update with your device connected? This should then download the drivers from the web. (If you are able to use the internet at some ones house etc.
Also if you are still having problems, go into the add and remove programmes and see if the device is listed, if it is, uninstall it. (make sure the device isnt connected) then reboot and reinstall the device.
You could also ask widnows to do a restore to a earlier part of windows (Before you connected the o2 modem)
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